X-ray apparatus



Sept. 14 1926. Y J. B. wAN'rz RAY APBARATUS Filed Feb. 9. 1921 4Sheets'-Sheet l INVENTOR. Ju/(us Wanfz @7.9M

4 Sheets-Sheetl 2 A TTORNEY Sept. 14 ,1926. J. B. WANTZ X-RAY APFARATUSFiled Feb. 9, l921 J. B. WANTZ X-RAY APPARATUS Filed Feb. 9, 1921 4Sheets-Sheet 3 Fig. 3

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A TTORNE Y Sept. 14 1926.

J. B. wANTZ X-RAY APPARATUS Filed Feb. 9. 1921 4 Sheets-Sheet 4 63 al'aq JNVENTOR. 4 BYL/u/l'us B. Wan Tz KW fx M A TToRNEy Patented Sept.14, 1926.

UNITED STATES PATENT ePRICE.

JULIUS B. WANTZ, OF OAK PARK, ILLINOIS, SSIGNOR TO VICTOR X-RAY CORPORA-TION, OF CHICAGO, ILLINOIS, .AA CORPORATION OF NEW YORK.

x-RAY APPARATUS.

Application led February 9, 1921. Serial No. 448,554.

My invention relates generally to X-ray a paratus for supporting inmovable condition relative to a patient, an X-ray tube and itscooperating e ement, as for example a fluorescent screen; my inventionrelating, more particularly, to apparatus intended for use in thesetting of broken bones and in the uoroscopic examination, orradiographing, of patients while in the condition of pneumoperitoneum, acondition produced, gener-ally stated, by the introduction of gas, suchas oxygen, into the peritoneal cavity to effect distention of the wallsof this cavity, for a urpose well known in the art.

In connection with the particular operations referred to, it may bestated that it is highly ldesirable that the X-rays be directed throughthe patient throughout a range o-f widely differing angles withoutdisturbing the patient and from a source the distance between which andthe portion of the patient to be observed, or radlographed, remains avide a construction of appara-tus wherein.n

provision is made for thus manipulatingan X-ray tube and its cooperatingelement, as for example, and more particularly, a

fluorescent screen, preferably so that these parts at opposite sides ofthe patient may move in unison in a curved path and maintain in theirdifferent positions of adjustment throughout such pat-hzthe desiredreratus from the right hand side of Fig. 1.

Figure 3 is a view in elevation of the mov` able frame on which theX-ray tube and the fluorescentscreen are supported, the

e base the apparatus is adapted to be firmly supported on the Hoor.Rising from the base preferably midway between its ends is a standard7supporting at its upper end a table, of material transparent to X-rays,

.for the patient,r this table which extends laterally from the standard7, being shown as pivoted midway between its ends to the standard, as bymeans of the "pivoting shaft 9 Journaled in the upper end of thestandard, the table 8 bein provided toward o posite ends with han les 10to facilitate t 1e rocking of the table on its pivot. The table 8 isprovided with a depending portion 1l containing an arc-shaped slot 12into which a stud 13"carried by the standard 7, projects, the outer endof this stud being proyided with any suitable means for presentmg, tothe swinging movement of the table 8 upon its pivot 9, a desirabledegree of friction, these mea-ns as shown comprising ment at its upperend with the notched porL tion of the rack17, against the resistance ofa coil spring 22 surrounding this rod between the pedal 21 and thebracket 20, the purpose of this rod and rack being to lhold the table 8in the position to which it i is adjusted on its pivot 9. Rising fromthe portion 6 of the base, are two pairs of lugs 23 supporting parallelguide rails 24 held thereto by means of cap plates 25, these railsforming the support and guides for a frame, rep-resented at 26 servingas the support for the tube and screen-supporting mechanism. The supportjust referred to is formed of the end members 27 connected together bycrossbrace 28 at their lower ends and a cross rod 29 at their upperlaterally deflected ends. The members 27 are preferably of the formshown to provide the relatively wide base portions from which rise theportions 30 terminating in arc-shaped portions 31, the latter beingprovided with rollers 32 and 33 at their outer edges and with rollers 34at their inner edges. The supporting structure thus provided carries atits lower end, grooved rollers 35 and 36 located, respectively, aboveand below the guide rails 24 and serving to permit this supportingstructure to be moved lengthwise of the guide rails, but without dangerof displace ment thereon.

The primary support for an X-ray tube represented at 37 and theliuorescent screen represented at 38, in the particular constructionillustrated, is in the form of a framework comprising the arc-shapedtubes 39 connected together adjacent their opposite ends by crossmembers 40 and 4l and intermediate their ends by cross-members 42 and42a, the frame thus provided extending at its curved members 39 intoengagement with the rollers 32, 33 and 34, as shown, the rollers 32 and33 extending at one side of each of the members 39 and the rollers 34 atthe opposite side thereof and affording means whereby when the framejust referred to is moved up or down, it will move in a curved pathcorresponding with the curvature of its frame members 39, the parts ofthe apparatus being so'positioned and arranged, as shown, that themovement of the frame is in a plane extending transversely of,preferably at a right angle to, the longitudinal axis of the table 8.The frame just described is provided with a pair of rods 43 connected attheir opposite ends with the cross members 4l and 42 and extendingpreferably at right angles thereto, these rods forming guideways for asupport 44 in the form of a plate, for supporting the X-ray tube 37 andshutter mechanism hereinafter referred to, this plate being providedwith apeitured lugs 45 through which the rods 43 extend. The plate 44 iscentrally apertured as indicated at 46, and at opposite sides, at oneface thereof, is provided with bracket arms 47 spaced apart and in whichthe X-ray tube 37 is adapted to be held in a manner well understood inthe art, the tube being enclosed within a shield 48 which may be, by wayof eX- ample, of a form commonly made of lead glass, forV shielding theoperator from the X-rays emitted from the tube and preferably opaque toordinary light rays, as by coating it with black enamel. The tube shownis of the so-called Coolidge type employing high potential currentforproducmg the X-rays and a low potential current for energizing theheating coil of the tube, one of the high tension wlres represented at49 being connected with the terminal 50 of the tube and the two wires 51and 52 through which the low tension current is supplied to the heatingelement of the tube and over one of which the high potential currentflows, leading to a lplug 53 for makin the desired contacts wit the tubein accor` ance with common practice, the wire 49 being show n asengaging the outer end of an insulatmg arm 54 connected with the bar 4land thence extending in wound condition upon the reel 55 supported on abar 56 of insulating material connected at its ends with brackets 57rising from the base portions of the members 26, this reel beingconnected with one ofthe wires of the high potential circuit, in amanner not shown but which is well known in the art. The wires 51 and 52likewise extend over insulating arms 58 carried by the cross-bar 41, andengage reels 59 and 60, respectively, upon which they are wound, thesereels being supported on the bar 56 in insuiated condition from eachother, one of the wires 5l being connected with the other of the wiresleading from the source of high potentialcurrent, this wire and theother of the wires 51 and 52 being connected with any suitabie source oflow potential current, in a manner not shown but as will be understoodby those skilled in the art.

The tube-carrying plate 44 cooperates with means through the medium ofwhich it may be adjusted lengthwise of the rods 43, these means in theparticular construction shown comprising abar 6l carried by the plate 44and equipped with a rack portion 62, the teeth of which mesh with apinion 63 journaled in a lug 64 carried by the cross-bar 42, this pinionbeing rigidly connected with one end of a flexible shaft 65 whichextends into the cross-bar 42 and at its opposite end extends into oneof the frame members 39, this end of the flexible shaft terminating in aknob 66 journaled on general construction of the shutter mechaf nismshown isthat illustrated anddescribed in United States Letters PatentNo. 1,242,498 granted October 9, 1917, to J. B. Wentz, and thus detaildescription thereof is not necessary. It may be stated, however,

` as indicated at 76, with adjacent that the shutter mechanism as 'showncom-lV prises a pair of plates 68 and 69 exten parallel to each otherandsupported, eac at one end, on bars 70-and 71, respectively, which areguided, to have lengthwise movement, by rollers 72 and 73 on the plate44, these shutter plates being located adjacent one face of the plate 44and moving, `1n the movement of the rods 70 and 71 in oppositedirections, toward andv away from each other. The simultaneous movementof the rods 70 and 71 is effected by means of a rock lever 74 pivotedbetween its ends at 75 on4 the plate 44 and having pin and slotengagement ortions of the bars 70 and 71, the lever 4 having pin andslot connection at 77 with a ongitudinally movable bar 78 extending atright angles to the bars 70 and 71 and guidingly confined on the member44 by roll-V ers 79 thereon. The upper` end of the Vbar 78 is providedwith a rack 80, with the teeth of which a. pinion. 81 meshes, thispinion being journaled in a lug 82 on the crossmem ber 42, this pinionbeing connected with a flexible shaft 83 extending through a lug 84 onthe cross ymember 42 and through a sheathing 85 which lies within aportion of the one of the members 39 other than the one containing theflexible shaft 65, the outer end of the shaft 83 being rigidly connectedwith a hand wheel 86 journaled in a stud 87 on the frame member 39. Theother two shutter plates of the shutter mechanism are represented at 88and 89, these platesbeing at the rear side of the support 44 and connected with longitudinally movable rods represented at 90 and 91, theserods being oonnected together by a rock lever 92 pivoted between itsends at 93 to the plate 44 and having pin and slot connection at 94 and95 with the rods 90 and 91, whereby saidrods move lengthwisesimultaneously, but in the opposite direction upon lengthwise moving ofthe bar 90, the upper end of which is in the form of a rack 96, it beingnoted that the plates 88 and 89 move in a path at a right angle to thepath through which the plates 68 and 69 move, and that by the adjustmentof these plates the size of the opening presented therebetween andthrough which the X-rays pass from the tubeito the patient, may beincreased or diminished as desired. The rack 96 meshes with a pinion 97journaled in a lug 98 on the cross-bar 42, this pinion being rigidlyconnected with one end of a fiexible shaft 99 extending into a sheathing100 and lying within the adjacent one of the side membersA 39, thisflexible shaft being connected at its outer end with a hand wheel 101rotatable in a boss 102v on the member 39. The two hand wheels 86 and101 thereby serve to afford independently operable means, operated by`the operator, for independently moving the shutter plates of the pairs,thereof hernbefore mab-edt, to!

The-iiuorescent screen'38 is mountedllin a v pass in :their movementtoward 'ward and away from each other to vary the l frame 103 preferablytrunnioned at 104 to the arms105 of a .yoke-shaped frame 106 swiveledmidway between its ends, as indicated at 107, to a sup orting frame 108.The opposite side mem ers of this frame shown as formed of rods 109 areguiding'ly confined in slide bearings 110, wlth a sety screw 111 on oneof these bearings for holding the frame 108 in adjusted position, theseslide bearings bei'ng y adjustable v lengthwise along a pair of parallelsupporting guiding rods 112. One end of each rod is connected with thecross-member 40 and extends rearwardly and downwardly as shown, theserods beingconnected with elbows 11.3 connected with rods 114, the latterbeing connected with the cross-member 42a. One `of the guide members 112is provided with a set-screw 115 whereby these guide bearings which arerigidly connected together by a bar 116 may be held in adjusted positionon the'rods 112. j

From the foregoing description, it will be readily understood that inthe use of the apparatus the o erator, without disturbing the relativepositlons of the X-ray tube and the fluorescent screen, and wthoutchanging the position of-the patient n the table, may, by moving theframe described and in part formed of the tubes 39 along the rollers 32,33 and 34, thereby causing this frame to move in a .curved path, causethe X-'rays to be directed against the patient from diferent'anglesabout a given point as a center, which is of great advantage in thesetting of bones and the liuoroscopic examination, or radiographing, oforgans, especially when the patient is inthe condition of pneumo`peritoneum, and may also cause the patient to extend at any desiredangle to the vertical by tilting the table 8. In the particulararrangement shown the framework referred to and supporting the X-raytube and liucrescent screen may be moved in the circular path referredto throughout an arc of 90 or more, the rollers 32, 33 and 34 and thesaid frame-work .being so proportioned as to present a degree offriction causing this movable framework to remain in the position towhich it is moved by the operator, while permitting relatively easymovement of such framework, and the friction presented at the pivot ofthe table while preventing too ready swinging of the table in case ofunbalanced weight thereon, permits the operator to swing the table tothe desired angle.

As a means for limiting the rotation of the said framework to the leftin Fig. 1, stops, represented at 117 are 'provided on mitting of theadjustment of the iiuorescent screen, on vthe rods 112, into and out ofaposition' in which it is diametrically opposed to the X-ray tube.

The other adjustments described and illus- I tra-ted are also of, valuein connection with CII a paratus of this character; thus the adjust-vable" mounting 'of the plate 44 on the rods 43 permit this plate, andwith it the\X-ray tube, to be adjusted, by means of the rack and pinionmechanism described, into different; positions along these rods andconsequentl along the movable frame; the adjustab e mounting of theshutters on the plate 44 permit of the increasing or diminishing, andthe changing of the shape, of the opening through which the X-rays aredirected by theV tube against the patient; the mounting of therelatively stationary frame formed in part of the members 26, on therods 24', permit of the adjustment of this frame, and the parts carriedthereby, in a direction lengthwise of the table and consequentlyrelative to the patient; and the adjustment of the table 8, as by theoperator turning it upon its pivot 9, following the release of the rod.18 from the teeth of the rack 17, permits of the positioning of thepatient at any desired angle relative to the vertical.

It may be further stated that the various relative movements of theseveral parts as described, causes the apparatus to 'lend itself to thequick and effective shifting of the various parts thereof, under perfectcontrol of the operator and with the minimum amount of work andinconvenience to him. While I have illustrated and described aparticular embodiment of m invention, I do not wish to be understoo asintending to limit it thereto as the same may be variously modified andaltered without departing from the spirit of'my invention.

WhatI claim as new, and desire to secure by Letters Patent, is: p

l. In X-ray apparatus, the combination of a support presenting a guideof segmental circular shape presenting circular curvature lengthwisethereof, and a member for supporting an X-ray tube and a uorescentscreen'or radiographic plate, engaging said guide and movable along thelatter in an arc-shaped path, said tube and screen or plate beingdiametrically opposed at opposite sides of the center about which theare of said guide is described.

2. In X-ray apparatus, the combination of a table, a support presentinga guide of segmental circular shape presenting circular curvaturelengthwise thereof and extending screen or radiographie .plate scribedby said guide being located in a plane between the lanes in which thesides of said table exten and a member for supporting an X-ray tube .anda fluorescent engaging said guide and movable alon the latter in anarc-shaped path, said tu j and screen or plate being diametricallyopposed at opposite sides of the center about which thevarc of saidguide is described.

3'. In -ray apparatus, the combination of a support presenting a guidecurved lengthwise thereof, a member supporting an X-ray tube, saidmember engaging said guide and being movable along the latter in acurved path and formed of sections one of which engages said guide andthe other of which carries said tube and isv adjustable on saidfirst-referred-to section in a direction tangentially of said uide tovary the position of said tube on te guide-engaging one of saidsections, and a support for the patient, said member bein movable alonsaid guide independently o said last-name support.

' 4. In X-ray apparatus, the combination of a plurality of members, anX-ray tube on one of said members, said last-referred-to member beingconfined on the other of said members to move in a curved path andformed of sections one of which engages .said last-named member 4and theother of which carries said tube and is` adjustable on saidfirst-referred-to section in a direction tangentlally of said curvedpath to vary the Aposition of said tube on said first-referred'- tosection, and a support for thepatient, the one of said members carryingsa1d tube being movable along the other of said members independently ofsaid support.

5. In -ray apparatus, the combination of a support presenting a guidecurved lengthwise thereof, a member for supporting an X-ray tube and afluorescent screen, or radiographic plate, 'engaging said guide andmovable along the latter in an arcshaped path, said member being formedwith a holder for said screen, or radiographic plate, adjustablerelative to the main portion of said member, said tube and screen, orplate, being diametrically opposed -at opposite sides of the centerabout which Lucano member,l said tube and screen, or plate, be-

ing diametrically opposed at opposite sides4 of the center about whichthe arc of saldv guide is described, and a support for the patient, theone of said. members carrying said tube being movable on the otherthereof independently of said last-named support.

7. In X-ray apparatus, the combination of a support presenting a guidecurved len hwise thereof, a member for supporting -ray tube and auorescent screen, or radio aphic plate, engaging said guide and mova lealong the latter 4in an arc-shaped path, said member being Iformed wltha older for said screen, or radiographic plate,

adjustable relative to the main portionv of the member, and with aportion for holding the X-ray tube adjustable relative-to the body ofsaid member, said tube and screen, or plate, being diametrically opposedat opposite sides of the centerabout whichy the arc of said ide isdescribed, and a support for the patlent, said member being movablealong said guide independently of said lastnamed su port.

8. In )gray apparatus, the combination of a support presentlng a guidecurved lengthwise thereof, a member supportingan X-ray tube, said memberengaging'said guide and being movable alon the latter in a curved pathand formed o sections one of which engages vsaid guide and the other` ofwhich carries said tube and is adjustable on said' irst-referred-tosection in a direction tangentially of said guidato vary the posltion ofsaid tube on the guide-engaging. one of said sections, and a support forthe patient, the one of said members carrying said tube being 'movableon the other thereof independently of said last-named support.

9. In X-ray apparatus, the combination of a movably-supported member, aholder device or an X-ray tube adjustably mounted on said member, anadjustable shutter device operatively connected with said holder andmovable therewith in the adjustment of the latter, and means foradjusting said shutter device involving a part supported on said memberand with relation to which said shutter device is movable, said meansbeing constructed and arranged to permit said holder to be moved intodifferent positions, and with itsaid shutter device, Without disturbingthe adjustment of the shutter device relative to the holder.

10.. In X-ray apparatus, the combination of a -movably-supported member,a holder device for an X-ray tube adjustably mounted on said member, anadjustable shutter device operatively connected with said holder andmovable therewith in the adjustmento the latter, and means for adjustingsaid shutter device involving a flexible shaft on said member, means onsaid member and connected with said flexible shaft for rotatf .j

ing the latter, and means connecting said iexible shaft with saidshutter device, constructed and arranged to permit said holder to bemoved'into different positions and with it said shutter device withoutdisturbing vthe adjustment of said shutter device relative to' saidholder.

11. In X-ray'apparatus, .the combinationA of a movably-supported member,aA holder'4 device for an X-ray tube'adjustably mounted on saidmember,an adjustable shutter device operatively connected with saidholder and movable therewith in the ,adjustment of the latter, and meansfor ,adjusting said shutter device involving rack and pinion mechanismoperatively connected with said shutter dev1ce, a flexible shaftconnected withl said pinion and carried by said member, and

means on said member for rotating .said ex-l y ible shaft. i

12. In Xerayapparatus, the combination of a plurality of members, and anX-ray tube and a fluorescent screen, or radiographic plate, on one ofsaid members, 'said' last-referred-to member being confined on I theother of' said members to move in an arc-sh-aped path, sai-d tube andscreen, or

plate, being located at opposite sides of the center aboutwhich said arcis described.

13. In Xray apparatus, the combination of a plurality of members, anX-ray tube and a iuorescent. screen, or radiographic plate, on one ofsaid members, said last-re- -ferred-to member being conned on the otherof said members to move in an arcshaped path, said tube and screen, orplate, 4being located at opposite sides of the center about which thesaid 'arc is described and a support for the patient, saidlast-referred-to member being movable lengthwise of said support in apath at an angle to the plane of said arc-shaped path.

14. In X-rlav apparatus, the combination of a support for a patient, anda plurality of. members one for supporting an X-ray tube and afluorescent screen, or radiographic plate, said last-referred-to'memberbeing movable on the other of said members in a curved path, to aposition in which said tube extends below that portion of said su portupon which the patient rests, said tuhe and screen, or plate, extendingat opposite sides of the center aboutwhich said arc is i andA screen, orplate, being diametrieally op- Y. posed relative to the center aboutwhich sald "rc is described.

Aof a member upon which the 16. In X-ra apparatus, the combination `of amember or supporting an X-ray tube and a fluorescent screen, orradiographic plate, and means supporting said member to move in anarc-shaped ath, said tube and screen, or plate, being ocated at oppositesides of the center about which said arc is described.

17. In'X-ra apparatus, the combination of a su port or a patient, and aplurality of memers one for supporting an X-ray tube and a fluorescentscreen, or radiographic plate, said last-referred-to members beingmovable on the other of said members, in an arc-shaped path, said tubeand screen, or plate, being located at opposite sides vor the centerabout which said larc is described, and said last-referred-to memberbeing movable in said arc-shaped path to a position in which said tubeextends below that portion of the support upon which the patient rests.

18. In X-ray a paratus, the combination of `a plurality o members, andan X-ray tube and a uorescent screen, or radioaphic plate, on one ofsaid members, said ast-referred-to member being confined 'on the otherof said members to move in an arc-shaped path, said tube and screen, orplate, being diametrically opposed relative to the center about whichsaid arc is described. y

19. In X-ray apparatus, the combination of a member upon which thepatient is supported, means supporting said member and adapting it to betilted into diilerent positions, a plurality of members adjacent saidrst-named-member, and an X-ray tube and a fluorescent screen, orradiographic plate,

on one of said plurality of members, said last-referred-to member beingmovable on the other of said plurality of members in a curved path.

20. In X-ray apparatus, the combination atient is supported, meanssupporting said) member and adapting it t`o be tilted into different'positions, a plurality of members adjacent' said rst-named-member, andan X-ray tube and a iluorescent screen, or radiographic plate, on one ofsaid plurality of members, said last-reerred-to member being movable onthe other of said plurality of members in an arc-shaped path, the centerof the arc described by said ath, being above said firstreferred-to memer and between the sides'of the latter.

21. In X-ray apparatus, the combination of a member upon. which th'eteient is supported, means supporting .said member and adapting it to4be tilted 4into different positions, a plurality of members adjacentsaid rst-named-member, and an X-ray tube and a liuorescent screen, orradiographic plate,

,on one of said plurality of members, said last-referred-to member beingmovable on the other of said plurality of members in a curved path,extendin crosswise of thelongitudinal axis of sai rst-named-member.

22. In X-ray apparatus, the combination of a table, and an X-raytube-holder, a holder for a fluorescent screen, or radiographic plate,means supporting said holders for rotation as a unit about a point abovethe table top asa center, and means supporting the top of said tablefor'movement into different angular positions relative to said holders.4 N

23. In X-ray apparatus, the combination of a table, and an X-raytube-holder, a holder for a fluorescent screen, or radiographic plate,means supporting said holders for rotation as a. unit about a pointabove the table top as a center, and means supporting the top of saidtable for movement into different angularV positions inv a planeextending' crosswise of the axis about which said holders rotate.

24. In X-ray apparatus, the combination of .a table for supporting apatient, a lurality of cooperating members one of w ich formsv asupport, an X-ray tube and iiuorescent screen, or radiographic plate, onthe other of said members, said supporting member extending at one sideonly of said table and said other member being movable on saidsupporting member in an arc-shaped path to a position in which said tube.extends beneath, and said screen, or plate, above, said table, saidtube and screen,`or plate, being diametrically opposed at opposite sidesof the center about which the arc o said guide is described.

25. In X-ra apparatus, the combination of a support or a patient, and aplurality of members, one for supporting an X-ray tube and a fluorescentscreen, or radioaphic plate, said last-referre'd-to member eing movableon the-other of said meml bers in an arc-shaped path throughoutsubstantially 90 degrees from a. position in which said tube extendssubstantially directlv below said support to a position in which itextends substantially along the side of said support, said tube andscreen, or plate, being diametrically oposed at opposite sides` of thecenter about which the are of said guide is described.

26. In X-ray apparatus, the combination of a table for supporting apatient, a plurality of co-operatmg members one of which forms asupport, an X-ray tube and fluorescent screen, or radiographic plate,onthe other of said members, said supporting member extending at oneside only of said table and said other member being movable on saidsupporting member in an arc-shaped path throughout substantially 90degrees from a position in which said tube extends" substantiallydirectly below said table and saidI screen, or plate, substantiallyabove said table to a position in which said tube and screen, or plate,extend substantially along the sides of said support, said tube andscreen, or plate, being diametrically senting a guide of segmentalcircular shape presenting circular curvature lengthwise thereof, and amember for supporting an X-Iay tube and a fluorescent screen, orradiographic plate, engaging said guide and movable along the latter inan arc-shaped path, said tube and screen, or plate, being diametrically'opposed at opposite sides of the center about which the arc of said uideis described, and said second support eing adjustable along saidfirst-named support in a substantially horizontal path irrespective ofthe tilted condition of said first named support.

28. In X-ray apparatus, the combination of a plurality of members, anX-ray tube and a fluorescent screen, or radiographic plate, on one ofsaid members, said last referred to member being confined on the v otherof said members to move in an arcshaped path, said tube and screen, orplate, being diametrically opposed at opposite sides of the center aboutwhich the arc of said guide is described.

JULIUSB. WANTZ.

